Family-centered prevention services for civilian dwelling military (CDM) families and children are rarely available in civilian communities or are often framed around mental disorders and family deficits. As of June 2010, over one million military service members from Operations Enduring Freedom, Iraqi Freedom, and New Dawn have become veterans. The potentially negative impact of wartime on veterans is well documented. Furthermore, wartime deployments can adversely impact the psychological health of children as well as marital relationships, parent-child relationships and overall family functioning. Although young children in CDM families may never have to cope with another parental deployment, their families may continue to struggle with the lasting effects of wartime deployment that cannot be ameliorated by singularly treating the service member. There is a need for family-centered preventive interventions that effectively build resilience and mitigate war deployment-related family difficulties, especially given the potential adverse emotional and developmental impact of deployment separations and reintegration stress on young children and their parents. To address this need, this study proposes to test the efficacy of FOCUS-EC (Families OverComing Under Stress for Early Childhood), an established strength-based, family-centered preventive intervention that is culturally sensitive and socially accepted by active duty military communities and has promising program evaluation data. A randomized control trial (RCT) will be conducted with 200 CDM families with young children, ages three to five years, recruited from Los Angeles and surrounding counties (200 veterans, 150 spouses, and 300 children). CDM families will be randomized to the FOCUS-EC intervention condition (n = 100 families; 100 veterans, 75 spouses, 150 children) or web-based educational materials condition (n = 100 families; 100 veterans, 75 spouses, and 150 children) and assessed at baseline, three, six, and 12 months. It is hypothesized that in the FOCUS-EC condition: 1) children will exhibit more positive social-emotional and behavioral outcomes and developmental competencies than children in the comparison condition, and 2) families will exhibit more positive family environment, improved parenting, enhanced parent-child relationships, and fewer parent psychological health problems than families in the comparison condition. Additionally, we aim to explore potential moderating effects of child health/development risk, military and deployment/separation history, exposure to combat/trauma during deployment, and veteran and spouse/partner background factors.